I'm in a similar boat to Moggie. Always dreamed of doing some big Overland trek, but needed to start off small due to family, job etc.
Over a pub lunch a mate and I decided to do the 2012 Shitbox Rally Melbourne to Cairns. Max budget is $1000, so we used a 1979 Fiat 131 Automatic picked up on eBay for $620. Preparation was limited to a paint job, roof rack, two spare tyres, a rubbish stereo (which packed up from the dust) and a CB radio. Other than grot in the carby and a handbrake cable coming adrift it had no problems.
For the 2013 I signed up again with a different mate. We wanted to take a Mini or a Moke. We were donated an extremely rusty Mini Van which we made live again with as many used and donated bits we could scrounge (remember $1000 budget!). On the journey the head gasket blew twice, the fuel pump quit and we burnt a few valves running crap outback fuel. But we made a 9000km loop across Aus and back by patching it up and keeping going. The Mini is now being prepped to go again in 2014.
Now most people think cars like this are "too old". Yes, they are more likely to break than the ten year old sedans you can pick up for $1000. But at least when they do break you can fix them at the side of the road with limited parts. I've been playing with and travelling in Minis my entire life and there is very little I can't fix at the side of the road.
If I took my 2009 Pathfinder on an overland trip and something broke, I'd be screwed. So I hope to one day do the trip in my Moke. I'm slowly building it up for the trip. It now has twin fuel tanks, 1275cc engine, larger capacity cooling system, strengthened subframes and suspension, raised ride height (since these photos), skid plates, custom dashboard, comfortable seats etc.
Yes, I know it's crazy to set off across the world in a Moke. But heck, that's part of the appeal. People manage it on Mopeds and survive!
Besides, taking my Moke, a Mini, or even my 74 Beetle then there is very little I can't fix at the side of the road. At worst air freighting in parts is easy because I know what bits I need and which specialists I can order them from.
I can understand why people want to do overland journeys in new vehicles. But it's definitely not for me. I'd rather have something I can fix. Trials are part of the adventure.